Combining with the amino acid gamma-aminobutyric acid (GABA, 4-aminobutyrate) to initiate a change in cell activity. GABA-A receptors function as chloride channels.
Comment
Note that this term represents an activity and not a gene product. Consider also annotating to the molecular function term 'chloride channel activity ; GO:0005254' and 'inhibitory extracellular ligand-gated ion channel activity ; GO:0005237'.